Foot controller for dental instruments

ABSTRACT

A compact and completely air-operated foot controller for dental instruments has a peddle operated by lateral pressure against a roller so as to have constant leverage, cam means for turning on air syringe and water syringe control air and for initiating flow of drill turbine drive air, together with means for adjusting the ratio between angle of peddle movement and extent of opening of turbine air regulator valve means. The initiation of flow is not affected by this adjustment.

United States Patent [191 Page [54] FOOT CONTROLLER FOR DENTAL INSTRUMENTS [76] Inventor: Richard W. Page, PO. Box 2583,

Chatharn, Mass. 02633 221 Filed: Mar. 1, 1971 [21 Appl.No.:119,538

[52] US. Cl. ..32/22 [51] Int. Cl ..A6lc 19/02 [58] Field of Search ..32/22, 23, 28, 25,

[5 6] I References Cited UNITED STATES PATENTS 12/1967 Maurer et al ..32/28 1 Apr. 10, 1973 3,296,698 l/l967 Staunt ..32/28 Primary ExaminerRobert Peshock Attorney-Sawyer & Kennedy [57] ABSTRACT A compact and completely air-operated foot controller for dental instruments has a peddle operated by lateral pressure against a roller so as to have constant leverage, cam means for turning on air syringe and watersyringe control air and for initiating flow of drill turbine drive air, together with means for adjusting the ratio between angle of peddle movement and extent of opening of turbine air regulator valve means. The initiation of flow is not affected by this adjustment.

5 Claims, 5 Drawing Figures PATEMEB APR 1 01975 SHEET 1 OF 2 FOOT CONTROLLER FOR DENTAL INSTRUMENTS BACKGROUND OF THE INVENTION Foot operated controls for dental instruments are in common use, including rheostats or pressure regulator valves for controlling electrically driven instruments or air driven instruments. A complete set of controls has generally not been supplied, and has tended to be bulky due to the necessary size of reliable, durable, electrical control elements and circuitry.

Manual and automatic switch means have been provided for selectively controlling different instruments by the same peddle (e. g., Billin et al. US. Pat. No. 3,209,457 Such arrangements have been comparatively bulky and required a combination of air and electric control devices. It is the general object of the present invention to provide a completely air-operable foot controller, which is more compact than prior devices having comparable functions.

A further object is to reduce control element adjustments to a minimum, making the device still more com pact and simplifying its construction and servicing.

SUMMARY OF THE INVENTION The present invention provides means for controlling turbine drive air, air and water syringe fluid and chip air by cam-operated valve means including a constant leverage foot peddle for rotatively adjusting the cam position, valve operating cam follower members and an adjustable cam element for controlling turbine drive air with a changeable ratio between foot movement and valve movement while not disturbing the timing of the cam operations. The air-spray and water spray are controlled together, and a cutoff valve for the water spray control air provides for using air spray alone, when desired. The chip air is controlled by auxiliary peddle means and utilizes the same air connectionas the spray air.

In my prior applications Ser. No. 34124, filed May 4, 1970, for Dental Instrument Hose Clip, and Ser. No. 55664, filed July 17, 1970, for Dental Instrument Operating System, I have disclosed an air-operated system and selector valve mechanism suitable for use with the controller of the present invention, and the present application is a continuation in part of those applications. However, the controller may be used with other such systems and mechainisms, where applicable.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a plan view, with cover largely removed, of a foot-controller embodying the invention in a preferred form;

FIG. 2 is a side elevation of the foot-controller of FIG. 1;

FIG. 3 is a section on the line iiiiii of FIG. 2;

FIG. 4 is a fragmentary view on the line iv-iv of FIG. 1; and

FIG. 5 is a detail plan view of a modified. form of cam.

The foot-controller comprises a base 1 and cover 2, which support and house the operating elements. The air connections may be housed. in flexible plastic hose 3, and consist merely of tubing (not shown) attached to fittings 5, 6, 7 and 8 for supply of air, discharge of tur bine drive air, discharge of air-spray air (also chip air) and discharge of water-spray control air, respectively. The controlled system may be as described in the above-mentioned applications and will not be described in any detail herein.

The operating members include the pedal 9 (which swings around a vertical axis), the treadle 10 (which moves up and down) and the water on-off lever 12 (which moves up and down). The first two elements are accommodated by a slot 11 in the front (right in FIG. 1 and 2) of the cover and the lever .12 passes through an aperture 13.

The foregoing elements and other mechanical features will be further described, following a description of the air circuitry. The air supply to the foot-controller through fitting 5 goes to air manifold 15 and from there takes several paths. A pressure regulating (MAR-lP)* (*This and other references are to Clippard Bulletin No, 267 of Miniature Fluid Power and Control Devices, to which reference may be made for details of structure of the elements.) valve 16 connects to the manifold 15 and supplies air at suitable pressure to airspray control (MAV-3) valve 17 and thus to outlet fitting 7. (The tubing connecting the elements shown is omitted, since it is standard and well understood and a showing of it would merely tend to obscure the disclosure.) Water-spray control air (application Ser. No. 55 664, supra) is also supplied from valve 16, going first through on-off valve 18 (MAV-3lP) and then through water-spray air control (MAV-3) valve 19 to the outlet fitting 8. Chip air is supplied at full pressure from manifold connection 20 to the chip-air (MAV-3P) valve 21 andfrom this valve to the same outlet (7) as the air spray. Manifold 15 also supplies the pressure regulating (MAR-1C?) or control valve 22 which supplies the air turbine driving air through outlet fitting 6.

In the usual drilling operation, both spray air and spray water will be used, but the water spray may be cut off when desired, by means of the lever 12 previously mentioned. This lever is carried on a pivot 25 secured to a bracket 26 (which also supports valves 17 and 19). With (the outer end of) lever 12 in down position (solid in FIG. 2), the arm 27 (Clippard cam follower Ser. No. 11925) is in outer position (to the right in FIG. 2) permitting valve stem 18' to remain out, so that valve 18 is open. If lever 12 is lifted with the toe, its inward end, which engages the roller of follower 27, cams element 27 back and pushes valve stem 18' into valve closing position, thus shutting off the waiter-spray control air and the water supply controlled thereby application Ser. No. 55664).

Chip air is turned on by depressing the outer edge of treadle plate 10. This plate is positioned over the base plate 1 by screws 30, the shanks of which pass through openings in plate 10. Springs (not shown) surround the shanks of screws 30 and force the plate 10 up against the screw heads, thus yieldingly holding the plate 10 in the horizontal position of the figure. When the outer end of plate 10 is depressed, its inner end lifts, forcing up the stem 21' of the chip-air valve, so as to supply chip air to the outlet 7 and thence to the dental instrument.

Pedal 9 controls theturbine drive air, spray air and water-spray control air. It carries at its outer end a rotatable roller 35, which turns on a vertical axis and protrudes out beyond the pedal profile both at the outer end of the pedal and at its face adjacent the foot of the operator. This insures engagement of the foot by the roller, giving a smooth and effortless regulation and also maintaining a set leverage or mechanical advantage. An angle arm 36 forms the middle part of the pedal and fastens to the generally cylindrical hub cam 37, which turns on a vertical axis concentric with its cylindrical outer surface. Hub 37 has a central bore 38 which fits pin 38 so as to mount hub 37 for free rotation thereon. Pin 38 has a reduced threaded lower end 40 which screws into the base plate 1, and a head 41 which is received in a countersink 42 in the hub 37 so as to hold it down.

The cam hub 37 is rotatively supported on bearing washer 43 and urged toward off position (clockwise in FIG. 1) by a torsion spring 44. Eccentrically adjustable stops 45 are positioned for engagement by the pedal middle section 36, so as to limit the pedal movement.

Valves 17 and 19, previously mentioned, are equipped with cam follower (Ser. No. 11925) elements 46 and 47 which have rollers entering a shallow groove in the cylindrical dwell surface of the cam 37, so that the first part of the pedal movement opens the air and water spray control valves 17 and 19.

The turbine air control valve 22 is operated by engagement of its stem 22 with cam follower 48, which is pivotally mounted on support post 49 and has its roller 50 pressed against cam element 51,carried on the cam hub 37, by the valve rod spring (not shown) of the valve 22. One side 52 of the hub 37 is cut down, forming a flat surface supporting the cam element 51, which is fixed in adjusted position by screw 53 accommodated by the arcuate slot 54. A block 54' is fastened in a groove in the cam 37 and carries a plate 55 which extends up above surface 52 but is below follower 48, so as not to interfere with its movement. The inner face of plate 55 forms a corner with the wall 56 of the cut down area 52, and is at an angle of about 120 thereto. Cam element 51 has a right angle knife edge comer 57 which fits in the corner formed by plate 55 and wall 56. The arcuate slot 54 is concentric about this comer, so that adjustment of cam element 51 does not vary the position of the knife edge. In the off position (FIG. 1) knife edge 57 (preferably having no more than about 0.005 inch radius) engages cam follower roller 50 in the position shown. As the pedal is moved, the plane cam surface 60 forces the cam follower 48 (clockwise in FIG. 1) back against valve stem 22, thus thus operating valve 22 to regulate the pressure of the turbine driving air supply.

Adjusting plate 51 (by about 10 from the position of FIG. 1) so that its cam surface 60 lies against plate 55 will increase the rate at which valve 22 opens as the pedal is moved. In this position of adjustment, cam surface 60 is tangent to roller 49.

Adjusting plate 51 in the other direction (about 20 clockwise in FIG. 1) so that its long edge lies against wall 56 will reduce the rate of valve opening to a minimum. In this position, the cam surface 60 is tangent to the path of movement of its knike-edge corner 57 about the axis of hub 37.

The form of cam may be varied, and the design permits easy interchange of cams. FIG. 5 shows a substitute cam plate 51', in which the trailing end of cam surface 60 is rounded off or curved, as indicated at 601:. Further, the plate 51 is formed at its other end with a curved cam surface 60y and has a second arcuate slot 54', similar to slot 54, but centered about the diagonally opposite corner of the plate 51'. Utilizing cam surface 60y requires merely removing screw 53, turning plate 51' end for end and replacing the screw 53. As in the case of plate 51, plate 51 (with either end thereof in use) may be adjusted between high and low rates by pivoting around corner 5556.

The following table shows, by way of example, some of the variations in the cam action, which may be obtained.

TABLE i ii iii iv v vi vii viii ix x xi psi ANGLE READINGS I 07 07 06 l7 07 05 l0 l0 l5 I4 23 ()8 09 O7 28 I7 I8 28 lo 08 20 20 ll 09 32 21 22 33 l3 l3 I0 36 24 24 37 I5 ll 36 25 l5 I2 39 27 27 42 l8 l9 13 42 29 29 48 22 I5 4l 30 23 I6 32 45 32 25 34 28 20 47 35 In the above table, column i gives outlet turbine drive air pressure readings, while columns ii and following give angle settings (in degrees) of the control pedal corresponding thereto, for different instruments, maximum pressure and cam surfaces adjustments. Thus, as is evident, columns ii, iv, v, vi and vii relate to a psi turbine, while columns iii, and viii to xi relate to a 40 psi turbine.

Columns ii and iii correspond to high and low rate settings, respectively, of cam 6060x, while columns iv and v correspond, respectively, to low and high rate settings of the same cam surface. Columns vi and vii (as also columns x and xi) correspond, respectively to low and high rate settings of straight cam surface 60 of FIG. 1. Columns viii and ix correspond to low and high rate settings of curved cam surface 60y. All columns relate to high speed handpieces, except column x, which relates to a low speed instrument.

By selecting cam profiles and adjustment position, the foot controller adapts readily to various combinations of particular instruments which the user may find desirable.

What is claimed is:

1. In a foot controller for dental instrument operation, air valve control means for an air turbine, and for air and water spray controls, comprising a rotatable cam member,air and water spray controlling valves operated by an initial movement of the cam, adjustable cam means carried by the cam member and a pressure regulating valve controlled thereby for controlling turbine driving air supply, a foot pedal for turning the cam member, and means for varying the ratio of valve movement to pedal movement by adjustably positioning the said adjustable cam means.

2. In a foot controller according to claim 1, a pedal having a roller for engagement by the foot, whereby the pedal leverage remains constant throughout a range of adjustment.

3. In a foot controller according to claim 1, adjustable cam means comprising a knife edge element and a cam follower roller engaged by the knife edge, and

5. In a foot controller according to claim 4, a substantially flat cam surface adjacent said knife edge, and in which the cam element adjusts pivotally between positions where the said surface is tangent to the follower roller and to the path of movement of the knife edge comer, respectively, when the knife edge engages the roller. 

1. In a foot controller for dental instrument operation, air valve control means for an air turbine, and for air and water spray controls, comprising a rotatable cam member,air and water spray controlling valves operated by an initial movement of the cam, adjustable cam means carried by the cam member and a pressure regulating valve controlled thereby for controlling turbine driving air supply, a foot pedal for turning the cam member, and means for varying the ratio of valve movement to pedal movement by adjustably positioning the said adjustable cam means.
 2. In a foot controller according to claim 1, a pedal having a roller for engagement by the foot, whereby the pedal leverage remains constant throughout a range of adjustment.
 3. In a foot controller according to claim 1, adjustable cam means comprising a knife edge element and a cam follower roller engaged by the knife edge, and means for setting the said element in different positions while pivoting around the knife edge, whereby the cam rate may be adjusted without substantial variation in the point at which it commences to act.
 4. In a foot controller according to claim 3, a said knife edge element having a right angle corner, and positioning means comprising an obtuse corner in which the right angle corner seats pivotally.
 5. In a foot controller according to claim 4, a substantially flat cam surface adjacent said knife edge, and in which the cam element adjusts pivotally between positions where the said surface is tangent to the follower roller and to the path of movement of the knife edge corner, respectively, when the knife edge engages the roller. 